Fix typo duplicate period in a docstring in the zipfile module. (GH-12326)

diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index dc16f6d..61cd929 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -879,7 +879,7 @@
 
     def read(self, n=-1):
         """Read and return up to n bytes.
-        If the argument is omitted, None, or negative, data is read and returned until EOF is reached..
+        If the argument is omitted, None, or negative, data is read and returned until EOF is reached.
         """
         if n is None or n < 0:
             buf = self._readbuffer[self._offset:]